When he was a young boy Finn McCool would spend time with Fingas on the banks of the River Bush. Fingas was a wise old man and a poet who taught  Finn about many subjects including the stories of Ulster's heroes and heroines.    The old man had been living alone for many years beside the river Bush in a small wooden cabin and had a special reason for doing so.  He kept  a close eye on the river Bush, day and night, hoping to catch the legendary’ 'Salmon of Knowledge'.   This was no ordinary salmon, this salmon had been raised far up the river Bush beyond Armoy  in a deep pool surrounded by nine hazel trees known in local folklore as the 'Well of Wisdom'. The salmon was not like any  salmon, if was large, it returned to the river whenever it felt to and never aged. 

When it was growing up it ate one hazelnut that had fallen into the pool from each of the nine trees and by doing so had gained all the knowledge from the well of wisdom.  It was also said that the first person to eat this salmon would gain all the knowledge it possessed.  Everyone who had so far tried to catch it had failed because the salmon had a special ability to send to sleep anyone who looked in its eyes. Fingas knew all of this, having been put to sleep several times before but he still hoped that where others had failed he would succeed.  One day  as Fingas and Finn were  sitting chatting by the river  the legendary salmon rose from the water, Fingas was always prepared and quickly grabbed his net and cast  it out across the river.

On the last turn, one of the sticks broke and the salmon started to slip towards the fire, Finn quickly stopped it with his hand and burnt a finger in the process which he immediately put in his mouth to soothe the pain. The salmon was cooked so he went and woke Fingas. On seeing Finn he noticed something different about him and asked, 'did you eat any of the salmon'. ? No, I did exactly as you said replied Finn. Why do you keep putting your finger in your mouth? Finn told him what had happened. Fingas then knew that Finn had unknowingly received all the knowledge from the salmon. He knew that this was destiny and that Finn was the rightful recipient. Finn went on to become a wise and fearsome warrior, the guardian of the king of Ulster and the leader of the Fianna, an elite group of warriors.

The  'Book of  Leinster'  was written in the 13th century, and tells the story of Amergin, a poet from the river Bush who grew up to become the chief poet to the King of Ulster.  It describes him as a warrior poet and chief of his clan, he is described as wearing a blue, fine bordered shirt next to the skin, with carved and interlaced clasps of white bronze, with buttons burnished gold in its opening and breast; above this he wore a coat of the most beautiful colours.  He was the son of a master blacksmith named Uel who lived at Ballaghmore beside the river Bush, on the farthest edge of  the Kingdom of  Dalriada. Amergin was born dumb and never spoke until he was fourteen years old.

On the day he spoke for the first time, Athern, Ulster ’s chief poet, had sent his servant to the blacksmith's to order a new axe to be forged. While he was there, Amergin began to speak but not in a normal way, he spoke very articulate and poetically. The servant listened in total amazement at the flow of words, he had never heard anything like it before not even from his master Athern, he was both shocked and surprised as he knew Amergin was dumb. When the servant on arriving home he told Athern about the miracle that had happened. Althern felt very threatened by this and over a few days, he resolved to kill Amergin in fear that he would take his place as the chief poet of Ulster.

Amergin’s father also realised this possibility and made a likeness of his son, dressed it in clothes and set it down in the corner of the smithy. When it was time to collect the axe, instead of sending the servant Athern came himself. He lifted the axe admiring the beauty and craftsmanship, at the same time he a noticed the shape of a boy sitting in the corner which he was convinced was Amergin. He took the new axe and swung as if admiring its power and balance, then suddenly he rush over and brought the axe down on the likeness of Amergin and then turned and fled, thinking he had killed him. 

Amergin’s father also forged swords for the King of Ulster, so the word soon spread to the king about what had happened. When the king heard about this he called for Athern’s to come to see him. As punishment the king ordered Athern to take Amergin as his foster son and teach him all the prose he knew, so Amergin could hone his gift with words. Soon Amergin became the chief of all the poets of Dalriada and afterwards the chief poet to Connor McNeese, the King of Ulster. He married the sister of the King and their son was the Ulster warrior Conall Cernach.